A method for controlling a control surface multirod actuator arrangement and the arrangement including: a first and a second multirod actuator configured to move or clamp around a first set of piston rods; a third multirod actuator configured to move or clamp around a second set of piston rods; a control unit configured to control motion of the first set of piston rods in a first motion mode and to control motion of the second set of piston rods in a second motion mode. Steps are moving at least one piston rod of first set of piston rods and/or clamping in parked position at least one piston rod of the second set of piston rods.

A vehicle architecture and the associated method of operation for fixed wing aircraft transition from operation underwater to flight in air. More particularly, the vehicle architecture and method allow transition and long-range operation in both water and in air.

The method starts with the vehicle oriented for long range flight in water. The method is composed of a flight orientation change for high speed ascent by rolling over, then water ascent, tractor propeller transition, wing transition, pusher propeller transition, boundary layer flight, and air ascent. The vehicle will ascend in its highspeed water configuration. As the tractor propeller breaches the surface of the water it will change its pitch collectively to optimize for low speed operation in air. As the wings breach the surface of the water, they will increase in camber to optimize for low speed operation in air. The vehicle will change angle of attack to stay within the ground effect regime in air using firstly the submerged control surfaces. In ground regime flight the vehicle will accelerate and transition to high altitude low drag flight with optimally cambered wings.

A passively controlled fluid foil has a span; and a rigid spar extending in the spanwise direction, a cellular material and a flexible outer surface defining a profile of the outer surface of the foil and encapsulating the cellular material and the spar.

An actuator arrangement for an aircraft flexible control surface comprises a base and a rotary element having a joint axle articulated on the base. The actuator arrangement comprises at least two attachment struts, each having three joint axles. A first joint axle is rotatably articulated on the rotary element. A second joint axle, arranged at a first strut end, is configured to be articulated on a first control surface skin panel. A third joint axle, arranged at a second strut end, is configured to be articulated on a second control surface skin panel. The actuator arrangement also comprises at least one connecting element having one joint axle at both ends, a first joint axle being articulated on the base and a second joint axle being articulated on one of the two struts, and an actuator configured to rotate the rotary element relative to the base.

A method of designing a hypersonic vehicle includes selecting a shock shape; tracing a leading edge along the shock shape; selecting a base plane defining endpoints of the leading edge and rearwardly displaced from a front of the leading edge; and tracing stream surfaces back from the leading edge along the shock to the base plane in order to define an upper surface and a lower surface, wherein the upper and lower surfaces and base plane enclose a volume representing internal volume of the hypersonic vehicle. The lower stream surface is controllably morphable.

Provided is an actuator apparatus including a positioning actuator device configured to position a first carrier member of the actuator apparatus. The positioning actuator device includes a first hydraulic fluid actuator having a first clamping means and a second hydraulic fluid actuator having a second clamping means, wherein the first and second hydraulic fluid actuator are configured to alternately clamp around a guide arrangement for moving the positioning actuator device along the guide arrangement. The first carrier member is provided with a first coupling member configured to be releasable coupled to the positioning actuator device. A method of positioning a first carrier member by means of the positioning actuator device is provided.

The invention relates to a supporting structure (46) which is positioned in a fluid flow (44) and characterised in that it is configured to be elastically deformed, on at least one portion of the supporting structure (46), between a first idle state in the absence of external stress and a second deformed state in the presence of external stresses caused by the fluid flow (44) due to a change in the orientation of the supporting structure (46) and/or the fluid flow (44). The invention also relates to an aircraft comprising at least one such supporting structure (46).

A flow control device on a structure such that strain in the structure is at least partially transferred to the flow control device is disclosed having at least two states, or shapes, separated by an elastic instability region. The flow control device is arranged to rapidly transition, or snap through, from the first state to the second state when strain in the structure exceeds an activation threshold of the flow control device. A spoiler on an aerofoil may have a rest position where it is substantially flush with the low pressure surface and an activated position where it protrudes from the low pressure surface and modifies the airflow over that surface. The spoiler bends to move from the rest position to the activated position when the strain in the aerofoil crosses a threshold. The deployed spoiler reduces the lift on the aerofoil, acting to reduce the lift induced strain of the aerofoil to which the spoiler is attached.

An aircraft wing having a fixed root part hingedly connected to a moveable tip part is disclosed. The tip part is configured to pivot relative to the root part about a substantially horizontal axis, between a load-alleviating configuration in which the tip part is oriented relative to the root part such that at least one of the upper and lower surface of the tip part is positioned away from the respective surface of the root part and a flight configuration in which the upper and lower surfaces of the tip part are continuations of the upper and lower surfaces of the root part. The shape of the tip part is controllably switchable between a cruise shape in which the tip part has positive camber and a recovery shape in which the tip part has negative camber.

An edge-morphing arrangement for an airfoil includes a compliant upper surface and a compliant lower surface that are joined together. An actuator is coupled to a driven surface and actuated to move the driven surface and change the shape thereof, with the non-driven surface changing its shape in response to actuation of the driven surface. The upper and lower surfaces can be part of a sub-flap mounted to a traditional flap of the fixed wing of an airplane. The upper and lower surfaces can be mounted to existing structure in the flap, or the flap components can be mounted to the sub-flap. The upper and lower surfaces can alternatively replace the traditional flap in the fixed wing of an aircraft. The upper and lower surfaces are continuous and can be deflected upward, downward, or twisted in a span-wise direction relative to the flap or wing.